Night latch bolt stop



Nov. 3, 1953 A. ERKKILA n 2,657,946

NIGHT LATCH BOLT STOP Filed Nov. 5, 1949 2 Sheets-Sheet l INVENTOR ANDREW ERKKILA.

jb/5MM /aATToRNl-P/ Nov. 3, 1953 A.ERKKLA NIGHT LATCH BOLT STOP Filed Nov. 5, 1949 2 Sheets-Sheet 2 ANDREW ERKKILA ha ATTORNEY Patented Nov. 3, 1953 NIGHT LATCH BOLT STOI? Andrew Erkkila, Fitchburg, Mass., assignor to Independent Lock Company, Fitchburg, Mass., a corporation of Massachusetts Application November 5, 1949,. Serial' No. 125,773

(Cl. 292=169l 8k Claims.

This invention relates to night latches and more particularly vto a bolt stop for such night latches.

It is among the objects of my invention to provide in combination with the spring projectable latch bolt of a night latch having a stop either to hold back the spring projecting latch or dog the same, characterized by rigidity of construction and positiveness of operation including ease of assembly of such dogging element independently of the latch bolt and shank assembly thereof.

My invention aims to overcome the objection heretofore experienced in rim latches having latch stops to dog the latch bolt or to hold back the latch bolt in a retracted position and involves a sliding button supported on the latch casing, especially where such casing is arched and given irregular configuration by such casting processes. casings are formed of light weight material or materials which are not of highly shock resistant quality, the incorporation of support for a stop in the form of a slide has not proven satisfactory because of the tendency civ such slides to bind or be torn from their moorings by an accidental slamming of the doorl with the latch bolt dogged in the projected position and the difficulty of machining operations on the irregularly contoured casing.

Gther mechanism known to me involving slides and supporting stops within the casing or supporting plate interfere with the quick assembly of the latch bolt independently of the stop mechanism and do not afford a quick indication of the condition of this actuating element.

Accordingly it is an object of my invention to provide in combination with a rim latch of a locking mechanism to dog or hold back the latch bolt in projected or retracted position which is easily and economically installed and is positive in operation and may be manipulated easily and does not require expensive finishing machining steps to assure operation.

Still other objects of my invention reside in the provision of a back plate support for the key controlled retractor cam whereby key actuation to obtain a hold back position is achieved smoothly and with no torsional strain on the key used to manipulate the lock.

To attain these objects and such further objects as may appear herein, or be hereinafter pointed out, I make reference to the accompanying drawing forming a part hereof, in which- Figure 1 is a front view of a rim night latch In such assembly, especially where the *removed to disclose the inside mechanism;

- door face.

Figure 4 is a section taken on the line 4-4 of Figure 3;

Figure 5 is a fragmentary longitudinal View taken on the line 5 5 of Figure 1;l

Figure 6 is a section taken on the line Iii- 6 ofk Figure 3;

Figure 7 is a fragmentary sectionofthe lock mounted upon a door;

Figures 8v and 9 are planviews of the back plate with the retractor cam shown in` normal and key operated positions respectively.

My invention may be summarized as providing in a rim night latch, in combination with the spring projected bolt thereof, of a stop element engaging ears orlugs of the latch bolt shank to dog the same in the retractedv position or in the projected position, and comprising a manipulatable pivotal button having finger piece exposed on the exterior face of the casing which operates on a swingingl base to project a dogging element into the path of a lug on the shank or into an unobstructing relationship characterized bya swinging support for such element, eliminating expensive machining operations yet requiring little force and minimizing the likelihood of damaging the casing which may not resist the shock of blows by reason of economies effectedin making the casing of cast inexpensive materials. Otherfeatures include a hold back camassembly for key operation which will eliminate the torsional strain on the key combined with hold back features for single hand operation.

Making reference to the drawing, I show a. rim night latch casing I0 of irregular outline arched transversely and longitudinally and provided with countersunk borings Il for attaching the casing to one face of the door, which will be readilyunderstood. The casing I0 has downwardly projecting side walls I2 and a rim I3 to abut the An end wall I4 is formed with the slot I5 through which( the latch bolt head II projects. The latch bolt shank comprises spaced branches Il, each of which branches has a headed wing I8 ridingin a guide I9 formed in the casing. The guide I9 is formed with seats 20., each seating one endof the helical expansion springs 2| at one end thereof and whose opposed ends are each centeredl on a pin 22 extending from the ears 23, laterally .directed from the shank branches Il.

The casing rotatively supports the turnknob 24, having the cams 25 for engaging the headed wings I8, in a manner well understood.

Extended from the inner surface 26 of the casing there is provided a post 21 integrally cast with the casing in the embodiment shown and having a shoulder 28 upon which the back plate 29 may be abutted and aixed by the screw 30. It Will be understood that the post 21 may conversely be supported on the back plate 29, reversing the engaging action, it being sufficient that the post 21 include means for holding together the back plate and casing, with provision for the spacer so that the binding screws do not warp the casing and restrain the sliding movement of the shank in the slides provided therefor.

In accordance with the features herein emphasized, I provide the post 21 with a transverse drill hole 3| running parallel to the axis of the shank of the bolt and supporting therein the screw pin 32. On this screw pin .there is pivotally mounted the stop button 33, having a counter-bored drill hole 34 for receiving the screw 35 and sleeve 36. The stop button 33 projects outwardly through a slot 31, projecting therethrough a head 38.

The stop button is formed or provided with a finger 39 to extend and ride in close adjacency to the post 21 and its movement swinging about the pin 35 and sleeve 36 is limited as to the span of the slot formed by the spaced shoulders 31a-31a extending from the button 33. Positive location or positioning is effected by the detent 40 supported in the slot 4I, spring projecting the head thereof against the cylindrical surface of the post 21, to hold the stop button in either of the positions limited bythe shoulders 31a-31a of the button 33 against the slot 31, and to secure seating by the snap action of the detent 40 against the angular faces 42-42 of the post to cam the detent into the depressed position.

The stop button is formed with an ear 43 which, in one position thereof, lies in the path of the lugs 44, 45 on one face of the shank branches I1, I1. The lugs 44, 45 are so positioned that upon depressing the latch bolt head I 6 to the fully retracted position, as shown in Figure 5, applying a swinging movement of the stop button 33 to bring it to the position shown in Figures 2 and 5, it will serve to direct the ear 43 to engage the lug 44 and hold the bolt head I6 in the retracted position. Likewise, in pushing the head 38 downwardly, as viewed in Figure 4, with the latch bolt in the projected position, as shown in Figures 3 to 6, the ear 43 will lie behind the lug 45 and dog the latch bolt I6 against depression.

In changing the "hand of the door to reverse the camming face of the latch bolt head lugs 44a and 45a on .the reverse sides of latch bolt shank are employed.

It will be observed that all of the stresses to which the button 33 is subjected in engagement with the lugs 45 or 45a is transmitted to the post 21 so that should the latch bolt strike the usual strike plate on the door frame, when the button is positioned to a point where the latch is dogged in the projected position, dislocation of the latch bolt mechanism is minimized. The employment of the pivotal sleeve 36 affords simple, almost frictionless swinging movement for the button 33, avoiding the necessity for any diicult machining of the rim casing, thereby permitting .the usc of cast material whether using metals or plastics, Without sacrificing strength for this element.

The latch bolt in its mounted position is shown in Figure 7, wherein the door frame is provided with a boring 5I, through which extends the cylinder 52 for operation by the key 53. Extended from the cylinder is the usual connecting bar 54 which projects into the cam 55 in keying engagement. The cam 55 is mounted in the eccentrically outlined bearing aperture 56 of the back plate 29 and includes the features of construction, shown in the patent to Brantingson No, 2,225,545 of December 17, 1940, which is concerned specifically with the construction of the retractor cam 55 and the manner of mounting the same in the aperture 56 formed in the back plate. The trunnion forming portion 51 of the retractor cam has extended therefrom the ears 58 for retaining the cam on the back plate 29 rotationally, and for ready assembly as will be understood by reference to said Brantingson patent.

It will be observed that the bearing portion 53 is eccentrically mounted for carrying out the hold-back features more specifically illustrated in the patents to Heineman Patent No. 2,454,920 of November 30, 1948 and Kalwo No. 2,454,928 of November 30, i948.

In accordance with the present invention, the cam'ears 60 and 6I are extended to either side of a connecting web 62. This section is arranged yto engage the camming face 63 on the leaf spring 64 which has its coiled end 65 anchored to the pin 66. An upstanding pin 61 serves as the fulcrum point for the leaf spring 64 resiiiently restraining the pressure exerted against the camming end 63 by either of the ears 60 and 6I when rotated and in whose path the cam end 63 is positioned during key operating rotation of the retractor cam 55 by the connecting bar 54. The pressure of the latch bolt through the head I6, as for example on the ear 60, shown in Figure 9, against the resilient pressure of the ear 6I in engagement with the camming end 63, throws the loosely journaled retractor cam 55 into the eccentric pre-dead center position serving to hold the latch bolt in the retracted position when key operated by the connecting bar 54.

It is to be understood that the connecting bar 54 is loosely connected with the key controlled plug and adjustable in the cutout 55a, to permit an eccentric shifting of the retractor bar to hold the latch bolt in the retracted position. By the employment of the spring 64 to have the bearing edges a and Bla in constant contact with the camming edge 63 of the spring 64, the spring tension on the head I8 of the latch bolt is counter-balanced throughout the rotational movement of the retractor cam to assure of smooth movement when key operated and minimize the torsional strain on the key and the connecting bar through which rotation of the retractor cam is effected.

Long life for one-hand operation with facility is thereby assured and slight turning influence on the retractor cam 55 restores the cam and the connecting bar key therewith to the normal position permitting withdrawal of the key 53 from the plug.

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent, is-

l. In a rim latch having a casing including a spring projected latch bolt, a bolt shank extending therefrom and guided within said casing, the combination having a manually operable stop button for dogging said latch bolt, said stop button having a manipulative head and a clogging ear extended therefrom, pivot means for said 5 button member within said casing, a slot formed in said casing through which said head projects. pivot supporting means within said casing for said pivot means, lug means on said shank cooperating with said ear for clogging said shank in one position of said stop button and pivotally movable to clear said lug means in another position of said stop button.

2. In a rim latch in accordance with claim 1 wherein said pivot means is along a line in parallelism with the bolt shank guide.

3. In a rim latch in accordance with cla-im 1 wherein said lug means are located at spaced points on said shank for dogging the latch bolt in engagement with one lug and holding the latch bolt in retracted position in engagement with another lug.

4. In a rim latch in accordance with claim 1 wherein said stop button includes detent means for holding said button in a manipulated position thereof.

5. In a rim latch in accordance with claim 1 wherein said pivot supporting means within said casing comprises a spacer post extending normal to the casing.

6. In a rim latch in accordance with claim 1 wherein said supporting means comprises a spacer post extending transversely of the casing 6 and said button includes an extension .nger cooperating with detent means on said post to hold said stop button in a predetermined manipulated position.

7. In a rim latch in accordance with claim 1 wherein said lug means comprises spaced lug members on opposite portions of said shank for dogging said latch bolt in diierent handed positions thereof.

8. In a rim latch in accordance with claim l wherein said stop button includes a nger extended to one side of said pivot means and said pivot supporting means comprises spacer means normally positioned with respect to said casing and detent means on said spacer adjacent said nger for holding said button in predetermined manipulated position.

ANDREW ERKKILA.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,137,800 Shaw May 4, 1915 1,148,549 Sparks Aug. 3, 1915 1,998,288 Roberts Apr. 16, 1935 2,268,743 Falk Jan. 6, 1942 2,279,591 Heyer Apr. 14, 1942 2,454,920 Heineman Nov. 30, 1948 

